2 * Distributed under the terms of the GNU GPL version 2.
3 * Copyright (c) 2007, 2008 The Board of Trustees of The Leland
4 * Stanford Junior University
12 #include <linux/slab.h>
13 #include <linux/vmalloc.h>
15 #include <linux/highmem.h>
16 #include <asm/pgtable.h>
18 static void *kmem_alloc(size_t);
19 static void *kmem_zalloc(size_t);
20 static void kmem_free(void *, size_t);
22 struct sw_table_hash {
26 unsigned int bucket_mask; /* Number of buckets minus 1. */
27 struct sw_flow **buckets;
30 static struct sw_flow **find_bucket(struct sw_table *swt,
31 const struct sw_flow_key *key)
33 struct sw_table_hash *th = (struct sw_table_hash *) swt;
34 unsigned int crc = crc32_calculate(&th->crc32, key,
35 offsetof(struct sw_flow_key, wildcards));
36 return &th->buckets[crc & th->bucket_mask];
39 static struct sw_flow *table_hash_lookup(struct sw_table *swt,
40 const struct sw_flow_key *key)
42 struct sw_flow *flow = *find_bucket(swt, key);
43 return flow && flow_keys_equal(&flow->key, key) ? flow : NULL;
46 static int table_hash_insert(struct sw_table *swt, struct sw_flow *flow)
48 struct sw_table_hash *th = (struct sw_table_hash *) swt;
49 struct sw_flow **bucket;
52 if (flow->key.wildcards != 0)
55 bucket = find_bucket(swt, &flow->key);
56 if (*bucket == NULL) {
58 rcu_assign_pointer(*bucket, flow);
61 struct sw_flow *old_flow = *bucket;
62 if (flow_keys_equal(&old_flow->key, &flow->key)) {
63 /* Keep stats from the original flow */
64 flow->init_time = old_flow->init_time;
65 flow->packet_count = old_flow->packet_count;
66 flow->byte_count = old_flow->byte_count;
68 rcu_assign_pointer(*bucket, flow);
69 flow_deferred_free(old_flow);
78 static int table_hash_modify(struct sw_table *swt,
79 const struct sw_flow_key *key,
80 const struct ofp_action *actions, int n_actions)
82 struct sw_table_hash *th = (struct sw_table_hash *) swt;
83 unsigned int count = 0;
85 if (key->wildcards == 0) {
86 struct sw_flow **bucket = find_bucket(swt, key);
87 struct sw_flow *flow = *bucket;
88 if (flow && flow_matches_1wild(&flow->key, key)) {
89 flow_replace_acts(flow, actions, n_actions);
95 for (i = 0; i <= th->bucket_mask; i++) {
96 struct sw_flow **bucket = &th->buckets[i];
97 struct sw_flow *flow = *bucket;
98 if (flow && flow_matches_1wild(&flow->key, key)) {
99 flow_replace_acts(flow, actions, n_actions);
107 /* Caller must update n_flows. */
108 static int do_delete(struct sw_flow **bucket, struct sw_flow *flow)
110 rcu_assign_pointer(*bucket, NULL);
111 flow_deferred_free(flow);
115 /* Returns number of deleted flows. We can ignore the priority
116 * argument, since all exact-match entries are the same (highest)
118 static int table_hash_delete(struct sw_table *swt,
119 const struct sw_flow_key *key,
120 uint16_t priority, int strict)
122 struct sw_table_hash *th = (struct sw_table_hash *) swt;
123 unsigned int count = 0;
125 if (key->wildcards == 0) {
126 struct sw_flow **bucket = find_bucket(swt, key);
127 struct sw_flow *flow = *bucket;
128 if (flow && flow_keys_equal(&flow->key, key))
129 count = do_delete(bucket, flow);
133 for (i = 0; i <= th->bucket_mask; i++) {
134 struct sw_flow **bucket = &th->buckets[i];
135 struct sw_flow *flow = *bucket;
136 if (flow && flow_del_matches(&flow->key, key, strict))
137 count += do_delete(bucket, flow);
140 th->n_flows -= count;
144 static int table_hash_timeout(struct datapath *dp, struct sw_table *swt)
146 struct sw_table_hash *th = (struct sw_table_hash *) swt;
150 mutex_lock(&dp_mutex);
151 for (i = 0; i <= th->bucket_mask; i++) {
152 struct sw_flow **bucket = &th->buckets[i];
153 struct sw_flow *flow = *bucket;
155 int reason = flow_timeout(flow);
157 count += do_delete(bucket, flow);
158 dp_send_flow_expired(dp, flow, reason);
162 th->n_flows -= count;
163 mutex_unlock(&dp_mutex);
168 static void table_hash_destroy(struct sw_table *swt)
170 struct sw_table_hash *th = (struct sw_table_hash *) swt;
172 for (i = 0; i <= th->bucket_mask; i++)
174 flow_free(th->buckets[i]);
175 kmem_free(th->buckets, (th->bucket_mask + 1) * sizeof *th->buckets);
179 static int table_hash_iterate(struct sw_table *swt,
180 const struct sw_flow_key *key,
181 struct sw_table_position *position,
182 int (*callback)(struct sw_flow *, void *private),
185 struct sw_table_hash *th = (struct sw_table_hash *) swt;
187 if (position->private[0] > th->bucket_mask)
190 if (key->wildcards == 0) {
191 struct sw_flow *flow;
194 flow = table_hash_lookup(swt, key);
198 error = callback(flow, private);
200 position->private[0] = -1;
205 for (i = position->private[0]; i <= th->bucket_mask; i++) {
206 struct sw_flow *flow = th->buckets[i];
207 if (flow && flow_matches_1wild(&flow->key, key)) {
208 int error = callback(flow, private);
210 position->private[0] = i;
218 static void table_hash_stats(struct sw_table *swt,
219 struct sw_table_stats *stats)
221 struct sw_table_hash *th = (struct sw_table_hash *) swt;
222 stats->name = "hash";
223 stats->wildcards = 0; /* No wildcards are supported. */
224 stats->n_flows = th->n_flows;
225 stats->max_flows = th->bucket_mask + 1;
226 stats->n_matched = swt->n_matched;
229 struct sw_table *table_hash_create(unsigned int polynomial,
230 unsigned int n_buckets)
232 struct sw_table_hash *th;
233 struct sw_table *swt;
235 th = kzalloc(sizeof *th, GFP_KERNEL);
239 BUG_ON(n_buckets & (n_buckets - 1));
240 th->buckets = kmem_zalloc(n_buckets * sizeof *th->buckets);
241 if (th->buckets == NULL) {
242 printk("failed to allocate %u buckets\n", n_buckets);
246 th->bucket_mask = n_buckets - 1;
249 swt->lookup = table_hash_lookup;
250 swt->insert = table_hash_insert;
251 swt->delete = table_hash_delete;
252 swt->timeout = table_hash_timeout;
253 swt->destroy = table_hash_destroy;
254 swt->iterate = table_hash_iterate;
255 swt->stats = table_hash_stats;
257 crc32_init(&th->crc32, polynomial);
263 /* Double-hashing table. */
265 struct sw_table_hash2 {
267 struct sw_table *subtable[2];
270 static struct sw_flow *table_hash2_lookup(struct sw_table *swt,
271 const struct sw_flow_key *key)
273 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
276 for (i = 0; i < 2; i++) {
277 struct sw_flow *flow = *find_bucket(t2->subtable[i], key);
278 if (flow && flow_keys_equal(&flow->key, key))
284 static int table_hash2_insert(struct sw_table *swt, struct sw_flow *flow)
286 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
288 if (table_hash_insert(t2->subtable[0], flow))
290 return table_hash_insert(t2->subtable[1], flow);
293 static int table_hash2_modify(struct sw_table *swt,
294 const struct sw_flow_key *key,
295 const struct ofp_action *actions, int n_actions)
297 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
298 return (table_hash_modify(t2->subtable[0], key, actions, n_actions)
299 + table_hash_modify(t2->subtable[1], key, actions, n_actions));
302 static int table_hash2_delete(struct sw_table *swt,
303 const struct sw_flow_key *key,
304 uint16_t priority, int strict)
306 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
307 return (table_hash_delete(t2->subtable[0], key, priority, strict)
308 + table_hash_delete(t2->subtable[1], key, priority, strict));
311 static int table_hash2_timeout(struct datapath *dp, struct sw_table *swt)
313 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
314 return (table_hash_timeout(dp, t2->subtable[0])
315 + table_hash_timeout(dp, t2->subtable[1]));
318 static void table_hash2_destroy(struct sw_table *swt)
320 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
321 table_hash_destroy(t2->subtable[0]);
322 table_hash_destroy(t2->subtable[1]);
326 static int table_hash2_iterate(struct sw_table *swt,
327 const struct sw_flow_key *key,
328 struct sw_table_position *position,
329 int (*callback)(struct sw_flow *, void *),
332 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
335 for (i = position->private[1]; i < 2; i++) {
336 int error = table_hash_iterate(t2->subtable[i], key, position,
341 position->private[0] = 0;
342 position->private[1]++;
347 static void table_hash2_stats(struct sw_table *swt,
348 struct sw_table_stats *stats)
350 struct sw_table_hash2 *t2 = (struct sw_table_hash2 *) swt;
351 struct sw_table_stats substats[2];
354 for (i = 0; i < 2; i++)
355 table_hash_stats(t2->subtable[i], &substats[i]);
356 stats->name = "hash2";
357 stats->wildcards = 0; /* No wildcards are supported. */
358 stats->n_flows = substats[0].n_flows + substats[1].n_flows;
359 stats->max_flows = substats[0].max_flows + substats[1].max_flows;
360 stats->n_matched = swt->n_matched;
363 struct sw_table *table_hash2_create(unsigned int poly0, unsigned int buckets0,
364 unsigned int poly1, unsigned int buckets1)
367 struct sw_table_hash2 *t2;
368 struct sw_table *swt;
370 t2 = kzalloc(sizeof *t2, GFP_KERNEL);
374 t2->subtable[0] = table_hash_create(poly0, buckets0);
375 if (t2->subtable[0] == NULL)
378 t2->subtable[1] = table_hash_create(poly1, buckets1);
379 if (t2->subtable[1] == NULL)
380 goto out_free_subtable0;
383 swt->lookup = table_hash2_lookup;
384 swt->insert = table_hash2_insert;
385 swt->modify = table_hash2_modify;
386 swt->delete = table_hash2_delete;
387 swt->timeout = table_hash2_timeout;
388 swt->destroy = table_hash2_destroy;
389 swt->iterate = table_hash2_iterate;
390 swt->stats = table_hash2_stats;
395 table_hash_destroy(t2->subtable[0]);
401 /* From fs/xfs/linux-2.4/kmem.c. */
404 kmem_alloc(size_t size)
408 #ifdef KMALLOC_MAX_SIZE
409 if (size > KMALLOC_MAX_SIZE)
412 ptr = kmalloc(size, GFP_KERNEL);
416 printk("openflow: used vmalloc for %lu bytes\n",
417 (unsigned long)size);
423 kmem_zalloc(size_t size)
425 void *ptr = kmem_alloc(size);
427 memset(ptr, 0, size);
432 kmem_free(void *ptr, size_t size)
434 if (((unsigned long)ptr < VMALLOC_START) ||
435 ((unsigned long)ptr >= VMALLOC_END)) {